An electric vehicle refers to an electrical connection type vehicle that receives and stores external power to use it in driving of the vehicle. Electrical connection type vehicles include a plugin hybrid vehicle, a battery vehicle, and a fuel cell vehicle. In recent years, due to the depletion of fossil energy and the environmental contamination, the demands on electric vehicles that use electrical energy have increased and the studies on them also have become more active. An electric vehicle generally stores electrical energy in a battery and is driven by rotating an electrical motor using the electrical energy, and the battery needs to be continuously charged because the capacity of the battery is limited. Accordingly, it is essential to charge the battery of the electric vehicle similar to fuelling an existing combustion engine vehicle at a gas station, and thus it is necessary to construct a charging system for the battery of the electric vehicle.
In this regard, Korean Patent Application Publication No. 10-2012-0109914 discloses a charging system of an electric vehicle that may be most general. According to the charging system of an electric vehicle, for example, power may be charged in the electric vehicle in association with an existing power network such as a city railroad power network. However, the charging system requires a separate fixed charging unit that may receive power from a power network and provide the power to an electric vehicle. Furthermore, the user needs to pay an electric fee at the very place where the fixed charging unit is provided after the battery of the electric vehicle is charged.
Meanwhile, Korean Patent Application Publication No. 10-2012-0012922 discloses a charging fee accounting system of an electric vehicle that may improve convenience and stability during a charging operation by attaching a charging fee accounting unit in the electric vehicle. According to the charging fee accounting system, because a charging station should be installed on a road surface even though the charging fee accounting unit is attached to the electric vehicle instead of a charging station on a road surface, enormous facility costs are required.
Accordingly, a charging system of an electric vehicle that may be conveniently used by the user of the electric vehicle while facility costs for charging and discharging the electric vehicle are reduced and may mediate a power price such that power may be purchased or sold between a power subscriber, a power sale company and the user of the electric vehicle is required.
Furthermore, an electric vehicle sometimes needs to receive power from a place that is not owned by the owner of the electric vehicle. For this reason, feeding units, such as a socket equipped with a user authentication function, a multi-tab, and an electric vehicle charger, for example, which allows the owner of an electric vehicle to connect the electric vehicle to a socket in a place that is not owned by the owner of the electric vehicle, for example, in a basement parking lot of an apartment complex to supply power to the electric vehicle. However, according to the feeding units, components for user authentication themselves consume power (hereinafter, standby power) during a standby operation. Furthermore, according to the existing feeding units, a person (for example, the owner of a building) who pays costs for the standby power may not coincide with the actual user (for example, the owner of an electric vehicle).